Project Summary/Abstract The objective of this NIH Mentored Research Scientist Development Award (K01) application is to provide additional training and research skill sets in three critical areas needed to conduct high priority research in HIV/AIDs-associated comorbidities. Specifically, the candidate will be skilled to conduct basic and translational research focused on the alcohol-mediated metabolic complications prevalent in the prematurely aged individuals infected with HIV on antiretroviral therapy. The applicant is a promising scientist with a track record of research in stem cells and signaling, which she now proposes to integrate with the field of alcohol-induced epigenetic alterations. The integrated and comprehensive plan to develop research skills will build the candidate?s expertise in epigenetic analysis, biostatistics, and translational research. The research proposal will focus on elucidating the mechanisms of alcohol-induced impairment of skeletal muscle (SKM) regeneration in SIV/HIV. Myoblasts isolated from chronic binge alcohol (CBA)- administered macaques show decreased myogenic gene expression and potential to differentiate into myotubes when cultured in vitro. Impaired myogenic differentiation was observed in the absence of in vitro alcohol exposure, suggesting that these myoblasts had a ?memory? that preserved gene expression changes. Preliminary evidence also suggests dysregulated muscle-specific microRNAs (myomiRs) in the SKM of CBA-administered SIV-infected macaques leading to the hypothesis that CBA impairs SKM regeneration in SIV/HIV infection through epigenetic modifications of myogenic gene transcription. This hypothesis will be critically tested by three specific aims. The first aim will test the prediction that CBA results in decreased myoblast myomiR expression and differentiation potential. To address this, the candidate will use her existing skills in stem cell culture and molecular techniques. In addition, she will be trained in in situ hybridization techniques for determining expression of myomiRs in myoblast cultures. The second aim will test the prediction that CBA-induced myoblast histone modifications contributes to decreased myogenic differentiation potential. Using molecular techniques target genes of myomiRs will be validated, histone deacetylase (HDAC) activity, and histone modifications will be determined. The third aim will establish the clinical relevance of altered myomiR expression in the circulation in a cohort of persons living with HIV/AIDS ( P L W H A ) with alcohol use disorders (AUD). Circulating levels of myomiRs will be correlated with AUD and muscle strength (hand grip dynamometer) to establish their potential use as indicators of impaired myogenic function. The overarching goal of the proposed and future studies is to identify targets to improve skeletal muscle function using physical (exercise) or pharmacological interventions. The integrated translational and transdisciplinary training plan will support the candidate?s progression to an independent productive career in the field of alcohol- induced epigenetic modulation of skeletal muscle regenerative potential and will contribute to the research training of the workforce required to conduct high priority HIV/AIDS related research in non-human primates and PLWHA.